Establish the physical validity of holographic gravitational cubic couplings

Establish the physical validity of gravitational cubic couplings in holographic descriptions of pure Yang–Mills theory beyond constraints from glueball spectra and static-force calibration, using gravitational form-factor data or other independent interaction observables.

Background

The paper emphasizes that glueball spectra constrain quadratic fluctuation dynamics, while the static force probes an effective string on the same background. These calibration observables do not independently validate the cubic couplings between a metric source and two glueball modes.

The paper therefore compares the full cubic vertices derived from a BCE-inspired Einstein–scalar–axion action with normalized heavy-target effective couplings against scalar lattice gravitational form factors. Although the heavy-target prescription improves the scalar comparison, the broader physical validity of holographic gravitational cubic couplings remains unresolved and requires further independent form-factor or interaction tests.